Routing an electrical signal past a downhole connection used for semi stiff wellbore intervention rod

ABSTRACT

An electrically-enabled semi-stiff wellbore rod and guide nose system is provided, the system including at least one electrical cable disposed in a semi stiff wellbore intervention rod, a termination housing having one end connected to the end of the rod, the termination housing containing fiber optic sensors and the at least one electrical cable, a crossover connected to the other end of the termination housing, a ported coupling connected to the end of the crossover on one end of the ported coupling and having a lower termination for connection to devices on the other end of the ported coupling, where the at least one electrical cable extends through the interior of the crossover from the termination housing and to the ported coupling, one or several pressure-tight tubing(s) surrounding the at least one electrical cable in the interior of the crossover, where the at least one electrical cable is not in pressure communication with the interior of the interior of the crossover, the at least one electrical cable terminating for electrically connectable reception by devices at the lower termination.

REFERENCE

This application claims the benefit of U.S. Provisional Application No. 61/186,286, filed Jun. 11th, 2009.

FIELD OF THE INVENTION

This invention relates to wellbore intervention rods and, in a particular example, providing electrical communication from the semi-stiff intervention rod to the lower end of a guide nose.

BACKGROUND OF THE INVENTION

A semi-stiff, spoolable “carbon” rod (commercialized by Ziebel AS of Norway) is deployable into a wellbore. The semi-stiff, spoolable characteristic of the rod enables the rod to be pushed into a wellbore in a manner similar to deployment of coiled tubing. A guide nose is typically attached to the lower, deployed, end of the rod.

Fiber optic sensing is incorporated in the rod and into the guide nose that is connected to the lower end of the rod. The fiber optic sensing typically measures various environmental parameters, such as distributed temperature sensing (DTS). Distributed temperature sensing (DTS) is typically measured along substantially the entire rod length. Point measurements are also taken at and in the guide nose. These point measurements typically include environmental parameters such as temperature, pressure, and vibration.

While fiber optic sensing has been successfully incorporated in the rod and into the guide nose, at least one of the inventors has recognized a need to add electrically-powered devices, including logging tools and intervention tools, unto the lower end of the guide nose. At least one of the inventors has recognized that these electrically-powered devices need to have electrical power made available to them, the electrical power made available from the lower end of the guide nose or an otherwise proximate location.

SUMMARY OF THE INVENTION

In one example, a device is provided having means for routing one or several electrical cables past one or several fiber optic sensors within a connection coupled to a semi stiff wellbore intervention rod.

In one example, a device is provided incorporating an electrical connection below a tool having one or several fiber optic sensors incorporated. In a further example, one or several fiber optic connectors are incorporated in a lower connection of a tool. In a further example, one or several fiber optic connectors and one or several electrical connectors are implemented in a lower connection of a tool. In another example, a hydraulic coupling is implemented in a lower connection of a tool.

In one set of examples, a system for providing an electrical path from an intervention rod to the end of a tool is provided. The system includes: a semi stiff wellbore intervention rod; and a tool mechanically attached to an end of the intervention rod. The intervention rod further includes an electrical wire emplaced within the rod, providing an electrical path, and an optical fiber emplaced within the rod. The electrical wire extends continuously out of the end of the rod into the tool. The electrical path extends to an electrical connector at the end of the tool, providing access to the electrical path on the exterior side proximate to the end of the tool.

In another example, the optical fiber extends into the tool. In a further example, the tool further includes a first chamber and a ported chamber, and the electrical wire extends into the first chamber of the tool. In another example, the electrical path extends through the ported chamber to the electrical connector at the end of the tool. In another example, the ported chamber is isolated from the first chamber. In another example, the pressure in the ported chamber is isolated from the first chamber. In another example, the optical fiber is optically connected to a sensor that is in communication with the ported chamber.

In another example, a system for providing an electrical path from an intervention rod to the end of a tool is provided. The system includes: a semi stiff wellbore intervention rod; and a tool mechanically attached to an end of the intervention rod. The intervention rod further includes an electrical wire emplaced within the rod, providing an electrical path, and an optical fiber emplaced within the rod. The tool further comprises a first chamber and a ported chamber. The electrical wire extends continuously out of the end of the rod into a first chamber of the tool. The optical fiber extends to a sensor that is in communication with the ported chamber. The pressure in the ported chamber is isolated from the first chamber. The electrical path extends through the ported chamber to an electrical connector at the end of the tool, providing access to the electrical path on the exterior side proximate to the end of the tool.

In one example, an electrically-enabled semi-stiff wellbore rod and guide nose system is provided, the system including at least one electrical cable disposed in a semi stiff wellbore intervention rod, a termination housing having one end connected to the end of the rod, the termination housing containing fiber optic sensors and the at least one electrical cable, a crossover connected to the other end of the termination housing, a ported coupling having a first end connected to the end of the crossover, and a lower termination disposed on a second end of the ported coupling for connection to devices, where the at least one electrical cable extends through the interior of the crossover from the termination housing and to the ported coupling, one or several pressure-tight tubing(s) surrounding the at least one electrical cable in the interior of the crossover, where the at least one electrical cable is not in pressure communication with the interior of the interior of the crossover, the at least one electrical cable terminating for electrically connectable reception by devices at the lower termination.

In at least some examples, one of the advantages of using such a tubing encased-cable solution, is that the cables will not be subjected to any wellbore fluids, and it also simplifies the construction and manufacturing of the mechanical housing system for the tool. Standard industry tube couplings, as for example the well-known “Swagelok”, can provide a seal tight connection for the tubing to the housing, cross-over's and similar.

In one example, the small diameter tubing is placed in the available area within the tool housing.

In one example, the same method as herein described is used to route one or several fiber optic cables, and/or hydraulic lines for operation of tools below, past a termination housing. In a further example, the connector in the lower tool end contains one or several fiber optic couplers, and, in a still further example, one or several hydraulic couplers.

SUMMARY OF THE SEVERAL VIEWS

FIG. 1 illustrates a 2-D cut-away view and example of a standard method of terminating a semi-stiff wellbore intervention rod.

FIG. 2 illustrates a 2-D cut-away view and example of an electrically-enabled semi-stiff wellbore rod and termination.

 1: termination housing  2: semi stiff wellbore intervention rod  3: pressure sensor  4, 5, 6: sensors  7: support material  8: epoxy or glue  9: injection port 10: crossover 11: crossover threads 12: ported coupling 12A: lower termination 12B: electrical connection 13: pressure-tight tubing 14: tools 15: electric cable 16: oil filled buffer tube

DETAILED DESCRIPTION OF EXAMPLES OF THE INVENTION

Ziebel AS of Norway has deployed and commercialized a semi-stiff, spoolable, rod system containing sensing fibers and/or electrical cable(s) for sensing. Ziebel uses the spoolable rod to provide services under the service mark “ZipLog”. The system is based on pushing the spoolable rod into producing and/or fluid injection wellbores. The spoolable rod is typically pushed inside a tubing string (production tubing) which is inserted into the well coaxially to the wellbore casing. The sensing elements incorporated into the spoolable rod make it possible to provide real time data to the surface about well conditions during production, injection and shut-in.

The intervention rod can be described as semi stiff, spoolable rod made from glass, carbon or other fiber reinforced plastic. In some examples, an intervention rod includes one or more insulated electrical conductors, one or more fluid conduits (steel tube or other tube) and/or optical fibers embedded therein. In some examples, the optical fibers are enclosed in a steel tube. In one example, the optical fiber includes spaced-apart Bragg gratings along its length at selected intervals to perform as a distributed temperature or pressure sensor.

FIG. 1 illustrates a 2-D cut-away view and example of a standard method of terminating a semi stiff wellbore intervention rod. FIG. 1 illustrates a standard method of terminating the semi stiff rod (2), where sensors (4, 5 and 6) are built into the termination housing (1), often referred to as “guidenose” or “bullnose”. The version illustrated contains fiber optic sensing only.

In one example, the device contains a pressure sensor (3), coupled to oil filled buffer tube (16) where this buffer tube is used to protect the pressure sensor element from direct contact with corrosive well fluids. The buffer tube (16) is housed within a crossover (10) that is coupled to the termination housing (1) by threads (11). The wellbore pressure reaches the sensor through a ported coupling (12) connected to the lower end of the tool system. In one example, sensors (4, 5 and 6) within the termination housing (1) are being supported to protect from impact and vibration by a support material (7).

In one example, the tool is secured onto the semi stiff rod (2). In one example, epoxy or glue (8) is injected between the rod (2) and the termination housing (1) via an injection port (9). In one example, injection port (9) is plugged off upon completion of installation. In other examples, other methods of securing the rod (2) to the termination housing (1) are be used, as for example mechanical gripping.

FIG. 2 illustrates a 2-D cut-away view and example of an electrically-enabled semi-stiff wellbore rod and termination. FIG. 2 incorporates the components as illustrated in FIG. 1, and additionally a lower termination (12A) for the semi stiff rod (2) is introduced. In this termination (12A), an electric cable (15) is incorporated. In one example, electrical cable is routed past the standard layout in the tool, and is then fed past the wellbore fluid exposed area, where the buffer tube (16) is located, within a pressure-tight tubing (13). In the lowermost end of the guidenose a dry mateable type electrical connection (12B) is incorporated. In one example, this connection provides the contact for tools (14) that are mounted into the lower end of the guidenose.

In one example, termination housing (1) and crossover (10) and ported coupling (12) form a tool that is mechanically attached to one end of the semi stiff wellbore intervention rod (2). Intervention rod (2) carries at least one electrical wire or cable (15) that is incorporated, integrated into, disposed within or otherwise emplaced within the fibrous composition of the rod. This electrical wire or cable (15) provides an electrical path within the rod (2). Intervention rod (2) carries at least one optical fiber {for example, as connecting pressure sensor (3) and sensors (4, 5, and 6)} that is incorporated, integrated into, disposed within or otherwise emplaced within the mechanically fibrous composition of the rod.

The electrical wire or cable (15) extends continuously out of the end of the rod (2) and into the tool. In one example, electrical wire or cable (15) extends continuously out of the end of the rod (2) and into a first chamber, such as the interior of termination housing (1). An electrical connector is not required as the protrusion of the wire or cable from the mechanically fibrous portion of the rod eliminates the need for an electrical connector. Upon exit from the mechanically fibrous portion of the rod, in one example, the electrical path of wire or cable (15) is extended by soldering additional wire or cable to reach along the length of the tool or otherwise forming an electrical connection to the end of the tool.

In one example, the interior of crossover (10) forms a ported chamber. At least one optical fiber extends out of the rod (2) and into the tool to a sensor, such as pressure sensor (3). The optical fiber is optically connected to a sensor that is in communication with the ported chamber. In one example, pressure sensor (3) is in communication with the ported chamber by the connection between pressure sensor (3) to oil filled tube buffer tube (16).

In one example, means are provided to isolate the first chamber from the ported chamber, as in one example, crossover (10) from termination housing (1). In one example, means are provided to isolate the pressure in the ported chamber from the first chamber, as in one example, pressure tight tubing (13) or buffer tube (16).

The electrical path of wire or cable (15) extends through the first chamber and the ported chamber to an electrical connector at the end of the tool, such as electrical connection (12B) that is connected to lower termination (12A). Access is therefore provided to the electrical path of wire or cable (15) on the outside (the exterior side) of the tool, approximately at the end of the tool.

In an example where no such tools are attached, the connection is sealed off using a blank plug. In another example, where tools are to be attached to the lower end that do not require electrical power, the connection to the first tool attached is sealed off from the connection by pressure-tight o-rings.

In one example, the device bypasses of one or several electrical cables within one or several tubes, and, therefore, provides an electrical connection in the lower end of the tool. To our knowledge, no tools having the combination of fiber optic sensing and electrical connection as herein described exist.

Other examples of the device are not dependent on: the rod diameters illustrated in these examples, how the guidenose is attached to the rod, or the design of the guidenose. One familiar with the technology will understand that various solutions for these attributes are possible.

In one example, a means is provided for routing one or several electrical cables past one or several fiber optic sensors within a connection coupled to a semi stiff wellbore intervention rod.

In one example, a device is provided incorporating an electrical connection below a tool having one or several fiber optic sensors incorporated.

In one example, a device is provided incorporating an electrical connection below a tool having one or several fiber optic sensors incorporated, where one or several fiber optic connectors are incorporated in a lower connection of a tool.

In one example, a device is provided incorporating an electrical connection below a tool having one or several fiber optic sensors incorporated, where one or several fiber optic connectors and one or several electrical connectors are incorporated in a lower connection of a tool.

In one example, a device is provided incorporating an electrical connection below a tool having one or several fiber optic sensors incorporated, where one or several fiber optic connectors are incorporated in a lower connection of a tool, and where a hydraulic coupling is implemented in a lower connection of a tool.

In one example, a device is provided incorporating an electrical connection below a tool having one or several fiber optic sensors incorporated, where one or several fiber optic connectors and one or several electrical connectors are incorporated in a lower connection of a tool, where a hydraulic coupling is implemented in a lower connection of a tool.

Various aspects of the invention, including alternative embodiments and the various functionalities associated therewith, are disclosed with particularity in the attached drawing sheets, FIGS. 1 & 2. The inventors submit that those of ordinary skill in the art will recognize and be able to appreciate the advantages of the apparatus, along with its associated methods and/or resulting systems.

Thus, the foregoing description is presented for purposes of illustration and description, and is not intended to limit the invention to the forms disclosed herein. Consequently, variations and modifications commensurate with the above teachings and the teaching of the relevant art are within the spirit of the invention. Such variations will readily suggest themselves to those skilled in the relevant structural or mechanical art. Further, the embodiments described are also intended to explain the best mode for practicing the invention, and to enable others skilled in the art to utilize the invention and such or other embodiments and with various modifications required by the particular applications or uses of the invention. 

1. A system for providing an electrical path from an intervention rod to the end of a tool, the system comprising: a semi stiff wellbore intervention rod; a tool mechanically attached to an end of the intervention rod; wherein the intervention rod further comprises an electrical wire emplaced within the rod, providing an electrical path, and an optical fiber emplaced within the rod; wherein the electrical wire extends continuously out of the end of the rod into the tool; and wherein the electrical path extends to an electrical connector at the end of the tool, providing access to the electrical path on the exterior side proximate to the end of the tool.
 2. The system of claim 1 wherein the optical fiber extends into the tool.
 3. The system of claim 2 wherein the tool further comprises a first chamber and a ported chamber, and wherein the electrical wire extends into the first chamber of the tool.
 4. The system of claim 3 wherein the electrical path extends through the ported chamber to the electrical connector at the end of the tool.
 5. The system of claim 3 wherein the ported chamber is isolated from the first chamber.
 6. The system of claim 3 wherein the pressure in the ported chamber is isolated from the first chamber.
 7. The system of claim 3 wherein the optical fiber is optically connected to a sensor in communication with the ported chamber.
 8. A system for providing an electrical path from an intervention rod to the end of a tool, the system comprising: a semi stiff wellbore intervention rod; a tool mechanically attached to an end of the intervention rod; wherein the intervention rod further comprises an electrical wire emplaced within the rod, providing an electrical path, and an optical fiber emplaced within the rod; wherein the tool further comprises a first chamber and a ported chamber; wherein the electrical wire extends continuously out of the end of the rod into the first chamber of the tool; wherein the optical fiber extends to a sensor in communication with the ported chamber; wherein the pressure in the ported chamber is isolated from the first chamber; and wherein the electrical path extends through the ported chamber to an electrical connector at the end of the tool, providing access to the electrical path on the exterior side proximate to the end of the tool.
 9. An electrically-enabled semi-stiff wellbore rod and guide nose system, the system comprising: at least one electrical cable disposed in a semi stiff wellbore intervention rod; a termination housing having one end connected to the end of the rod, the termination housing containing fiber optic sensors and the at least one electrical cable; a crossover connected to the other end of the termination housing; a ported coupling comprising: a first end connected to the end of the crossover, and a lower termination disposed on a second end of the ported coupling for connection to devices; wherein the at least one electrical cable extends through the interior of the crossover from the termination housing and to the ported coupling, and one or more pressure-tight tubes surround the at least one electrical cable in the interior of the crossover; and wherein the at least one electrical cable is not in pressure communication with the interior of the crossover, and the at least one electrical cable terminates for electrically connectable reception by devices at the lower termination. 